Method of making steam-jacketed kettle outlets



R. F. SALISBURY I 7 METHOD OF MAKING STEAM JACKETED KETTLE OUTLETS Filed Mar. 20, 1922 fllll/l/l wn-usss ug/E TR #40 ATTOR N EY-S Patented Apr. 3, 192 3,

' UNITED STATES PATENT OFFICE.

ALUMINUM COMPANY OF AMERICA, OF PITTSBURGH, PENNSYLVANIA, A CORPO- RATION OF PENNSYLVANIA.

METHOD OF MAKING STEAM-JAGKETED KETTLE OUTLETS.

Application filed March 20, 1022. semi No. 545,890.

T all whom it my concern:

Be it known that I, ROBERT FnoYD SALIS- BURY, a citizen of the United States, and a resident of New Kensington, in the county of 'Westmoreland and State of Pennsyl- Vania, have invented a new and useful Improvement in Methods of Making Steam: J acketed Kettle Outlets, of which the following is a specification.

This invention relates to a method of forming a tubular connection between two spaced metallic walls and particularly to an outlet connection for steam-jacketed kettles which must be of such character as to maintain the space between the walls hermetically sealed against comparatively high pressures.

It is the object of the invention to provide a method of forming such an outlet that is simple and easily performed, which will roduce-a hermetically sealed connection,- all oints of which are firmly and durably united, and which will not easily tear away when subjected to subsequent strains. It is a special object to form an outlet of the character referred to in which the walls and {the parts forming the same are made of a metal which loses or greatly diminishes in ductility when it becomes heated to a temperature approaching that necessary to effect a weld, or which has a high coefficient of expansion, or both, such as aluminum, and to obviate corrosion adjacent the joints of the finished connection.

The method can best be disclosed by illustrating and describing the same as actually performed in'connection with a typical device. A steam jacketed kettle of an approved type has, therefore, been selected and the invention as it is carried out in forming the outlet connection thereto will be described.

The single 'figure of the drawing is a fragmentary view partly in section and artly in elevation showing the finished outet connection to a steam jacketed kettle formed according to the invention.

The inner and outer shells or walls of the kettle are indicated at 1 and 2,. respectively, the same being spaced apart to provide a steam heating chamber therebetween, the lower portion of which is illustrated at 3.

The outlet in the embodiment shown is of tubular form adapted, to discharge the contents from within the kettle, through a pipe (not shown) threaded to its outer extremity.

If the walls 1 and 2 are made of aluminum, and other metals are used in the portions forming the connection which contact the aluminum parts, that is, if some of the parts of the connections are of aluminum and parts formed of other metals, such as brass, abut the aluminum parts, an electrolytic or other similar action has been found to be set up, causing a pronounced corrosion in and ad acent the joints between. the two metals. If all the parts are constructed of the same metal, and the metal is of such character as to lose. or greatly diminish in f-ductility when the same is highly heated,

"that is to a temperature approaching that necessary to effect a weld, or if such metal possesses a high coefiicient of expansion or both, it is extremely diffic-ult to secure a durable hermetically sealed welded-joint between the several parts which will effectively withstand the pressures of heating fluids often used, due to the stresses set up between the parts before the pprtions adjacent the weld have regained The invention produces a sim le and efiicient connection free of corrosion between the parts, strongly attached and tightly sealed. In the first place, all the parts are of the same metal thereby eliminating corrosion resulting from the cause above noted, and in the second place, a proper sequence in welding the several joints is followed, thereby, overcoming the disadvantages arising from the eir ductility.

physical properties of the metal, to pres- I ently described."

The inner shell 1 is flared outwardly around its central aperture 4 to form an annular lip 5 to which one end of the cylin- .drical tube 6 corresponding in thickness and cross-sectional dimension is welded as indicated at 7, tube 6 being of such length as to project through and for some distance beyond the aperture 8 in the outer .shell 2. The space between the exterior of the tube 6 and the edge of aperture 8 is closed by an apertured disk or annulus 9, the curvature of which adapts the same to fit the exterior surface of the shell 2, and the size of its central aperture is such as to form a snug fit around the exterior of the tube 6 After th t 6 h as el to t p 5A1:

and in which the several parts are' annulus 9 is positioned as shown in the I drawing and is welded to the tube adjacent the line of contact between the disk and tube as indicated at 10. The parts are then allowed to cool, after which the peripheral edge of the disk is welded to the shell 2, as at 11.

Experience has shown that with aluminum or metals having similar characteristics, as above noted if the disk 9 be welded at both lines of contact 10 and 11, eithersimultaneously or before the disk 9 has been cooled sufiiciently to resume its normal dimensions, the welds will be defective and weak due to the stresses set up between the disk and tube and disk and shell, respectively, caused by expansion and contraction of the parts, and the consequent drawing away of the same in conjunction with the lack or diminished ductility in the metal incident to its highly heated condition in the region of the welded joints.

Heretofore, many attempts have been made to weld the outer shell 2 directly to the periphery of the tube 6 but due to the peculiarities of metals of the class named, as above pointed out, the results were very unsatisfactory, a large percentage of the welded joints being defective to a greater or less extent. If, however a disk of suitable proportions is used and the parts are cooled after welding at 10 and beforethe disk-and shell 2 are welded together at 11, a perfect weld and hermetically sealed joint is secured capable of easily withstanding any pressures ordinarily used.

It is well known that more satisfactory welds can be secured provided the parts to be united are heated to substantially the same temperature during the welding process. By employing the present method it is found that the parts welded together can be brought approximately to the same temperature in the region of the welded connection resulting in substantially perfect welds. It is obvious that expansion and contraction of the tube 6 also tends to set up certain stresses, but due to the sequence of operations employed as above described,

the same do not tend to rupture the joint 10 due to the fact that the disk 9 is freely suspended during the firstwelding operation and becomes negligible from a practical standpoint during the welding. of the joint 11.

While the applicability of the invention has been described in connection with the use of metal parts, all of which are of aluminum, the walls connected being curved, and the main body of the connection being of tubular form, it is obvious that the invention is equally applicable to metals having similar characteristics and whether the walls be curved, irregular or straight. It is,

therefore, intended to limit the invention beyond that specifically set forth and wall, embracing the body with a close fitting apertured disk, welding the disk to the body,

cooling the disk, and welding the disk to the second named wall. a

2. The method of forming an outlet for steam jacketed kettles comprising two spaced metallic walls which consists in welding the tubular metal body to one wall, permitting the body to project through'an aperture in the other wall, positioning a snug fitting apertured disk over the body, welding the disk to the body, cooling the disk,-and welding the disk to the second named wall.

3. The method of forming an outlet for steam jacketed kettles comprising two spaced metallic walls which consists in welding a tubular metal body to a portion of one wall projecting towards the other wall and pering in the other wall, embracing the body with a close fitting apertured disk, welding the disk to the body adjacent their line of contact, cooling the disk, and welding the welding the peripheral edge of the annulus to the second named wall.

5. The method of forming an outlet for -mitting the same to extend through an open steam jacketed kettles comprising two spaced metallic walls which consists in forming an annular lip around an opening in one wall projecting within the space between the walls, welding vone end of a cylindrical tube to the lip permitting the opposite endof the tube to extend through and beyond an opening in the other wall, embracing the projecting end of the tube with a close fitting annulus, welding the annulus to the tube ad- 'jacent and throughout their line of contact,

cooling the annulus, and welding the annulus to the other wall.

6. The method of forming an outlet for steam jacketed kettles comprising spaced metallic walls which consists in forming an annular lip around an opening in one wall projecting within the space between the walls, welding one. end of a cylindrical tube to the lip to forma hermetically sealed joint and permitting the opposite end of the tube to extend through and beyond an opening in the other wall, embracing the projecting end of the tube with a close fitting annulus, welding the annulus to the tube adjacent and throughout their line of contact, cooling the annulus, and welding the peripheral edge :of the annulus to the exterior of the second named wall.

7 The method of forming an outlet for steam acketed kettles comprising two spaced walls made of metal possessing a high coefficient of expansion which consists in welding a tubular body of similar metal to one of the walls permitting the same to project through an opening in the other wall, embracing the body with a close fitting apertured disk also of the same'metal, welding the disk and body adjacent their line of contact, cooling the disk, and welding the disk to the second named wall.

8. The method of forming an outlet for steam acketed kettles comprising two spaced walls made of metal which loses or greatly diminishesin ductility when highly heated, which consists in welding a tubular body of similar metal to one of the walls permitting the same to project through an opening in the other wall, embracing the body with a close fitting apertured disk also of the same metal, welding the disk and body adjacent same to project through an opening in the othel'wall, embracing the body with a close fittlng apertured disk also of the same ma terial, welding the disk and body adjacent their line of contact, cooling the disk, and welding the peripheral edge of the disk to the second named wall.

10. The method of forming an outlet'for steam jacketed kettles comprising two spaced aluminum walls' which consists in forming an annular lip around an opening in one wall projecting towards the other wall, welding one end of a cylindrical aluminum tube to the lip permitting the opposite end thereof to project through an opening in the second named wall, embracing the projecting end of the tube with a close fitting annulus also of aluminum, welding the annulus to the tube, cooling the parts, and welding the annulus to the second named wall.

In testimony whereof, I sign In name.

ROBERT FLOYD SALI BURY. Witnesses:

Jos. T. WEINZIERL, P. B. HETRICK. 

